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  7. Kneeling Knee Tap To Crossed Reach

Exercise guide

Kneeling Knee Tap To Crossed Reach

  • Intermediate
  • Compound
  • Rep-based
  • Waist

This dynamic stability exercise integrates the posterior chain and anterior core, using a cross-body pattern to challenge the obliques and improve spinal control. It effectively builds functional core strength by requiring the body to maintain balance while moving opposite limbs.

Reviewed by the Crucible team · Updated June 2026

Watch the Kneeling Knee Tap To Crossed Reach demonstrationGuided video and your full workout live in the Crucible app.

Muscles worked

Primary

  • Abs
  • Obliques

Secondary

  • Erector spinae

Equipment

  • Body weight

Setup

  1. Begin in a quadruped position on all fours with your hands directly under your shoulders and knees under your hips.
  2. Engage your core to create a flat, neutral spine from head to tailbone.
  3. Distribute your weight evenly across your palms and the tops of your feet.

How to do it

  1. Simultaneously lift your right arm and left leg until they are fully extended and parallel to the floor.
  2. Exhale and crunch your midsection to bring your right hand and left knee together under your torso, tapping the knee with your hand.
  3. Inhale as you extend back out, reaching your arm and leg slightly across the midline of your body to emphasize the obliques.
  4. Return to the starting position with control and repeat the sequence on the opposite side, alternating for the duration of the set.

Form checklist

  • Keep your hips square to the floor; do not let them tilt or rotate during the reach.
  • Maintain a neutral neck by gazing at the floor about six inches in front of your hands.
  • Avoid arching your lower back when extending the leg; focus on glute contraction instead.
  • Keep the supporting shoulder 'packed' by pushing the floor away actively.

Pro tips

  • To maximize oblique engagement, focus on the 'crunch' phase by actively pulling your belly button toward your spine as the knee and hand meet.
  • Slow the tempo down to a 3-second extension to remove momentum and force the stabilizer muscles to work harder.
  • Imagine a glass of water resting on your lower back that you must not spill throughout the entire movement.

Make it harder

  • Perform the movement from a high plank position (knees off the floor) to drastically increase the balance and core demand.
  • Hold a light dumbbell in the reaching hand or wear ankle weights to increase the resistance on the glutes and shoulders.

Frequently asked

What muscles does the kneeling knee tap to crossed reach work?
The kneeling knee tap to crossed reach primarily targets the abs and obliques, and also works the erector spinae as secondary muscles.
What equipment do you need for the kneeling knee tap to crossed reach?
The kneeling knee tap to crossed reach requires no equipment — just your body weight.
Is the kneeling knee tap to crossed reach good for beginners?
The kneeling knee tap to crossed reach is rated intermediate. Build a base with simpler variations first, then progress to it with light load and strict form.

Related exercises

  • 3/4 Sit-UpBeginner · abs and obliques
  • 45 Degree Bicycle Twisting CrunchIntermediate · abs and obliques
  • 45 Degree Lean Back Alternate Knee RaiseBeginner · abs and obliques
  • 45 Degrees Arms PlankIntermediate · abs, deltoids, obliques, and pectorals

Train this with a plan, not guesswork

Crucible builds the kneeling knee tap to crossed reach into a precise program around your body, equipment, location, and time.

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